@redcoqui
Huh, they really don't mention it anywhere in the app, too. The string below is the user-agent DDG uses. So I would guess it's Chromium, because 88.0. etc is Chromium version, other parts must be for compatibility. My FF browser reports it's FF version.

Mozilla/5.0 (Linux; Android 10) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/88.0.4324.152 Mobile DuckDuckGo/5 Safari/537.36